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Three‐Dimensional Digital Evaluation of the Fit of Endocrowns Fabricated from Different CAD/CAM Materials
Author(s) -
Zimmermann Moritz,
Valcanaia Andre,
Neiva Gisele,
Mehl Albert,
Fasbinder Dennis
Publication year - 2019
Publication title -
journal of prosthodontics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.902
H-Index - 60
eISSN - 1532-849X
pISSN - 1059-941X
DOI - 10.1111/jopr.12770
Subject(s) - cerec , nanoceramic , cad , materials science , chamfer (geometry) , ceramic , dentistry , orthodontics , computer science , mathematics , engineering drawing , composite material , medicine , engineering , geometry
Purpose A wide variety of CAD/CAM materials are available for single‐tooth restorations. CAD/CAM material characteristics are different and may influence CAM fabrication accuracy. There is no study investigating the influence of different CAD/CAM materials on the final fit of the restoration. The aim of this study was to evaluate the fit of endocrowns fabricated from different CAD/CAM materials using a new 3D evaluation method with an intraoral scanning system. The null hypothesis was that there are no significant differences for the fitting accuracy of different CAD/CAM materials. Materials and Methods Preparation for an endocrown was performed on a maxillary right first molar on a typodont, and restorations were fabricated with a chairside CAD/CAM system (CEREC Omnicam, MCXL). Three groups using three different CAD/CAM materials were established (each n = 10): zirconia‐reinforced lithium silicate ceramic (Celtra Duo; CD), leucite‐reinforced silicate ceramic (Empress CAD; EM), resin nanoceramic (Lava Ultimate; LU). A 3D digital measurement technique (OraCheck, Cyfex AG) using an intraoral scanner (CEREC Omnicam) was used to measure the difference in fit between the three materials for a master endocrown preparation. The preparation scan and the endocrown fit scan were matched with special difference analysis software OraCheck. Three areas were selected for fitting accuracy measurements: margin (MA), axial (AX), occlusal (OC). Statistical analysis was performed using 80% percentile, one‐way ANOVA, and post‐hoc Scheffé test. Significance level was set to p = 0.05. Results Results varied from best 88.9 ± 7.7 μm for marginal fit of resin nanoceramic restorations (LU_MA) to worst 182.3 ± 24.0 μm for occlusal fit of zirconia‐reinforced lithium silicate restorations (CD_OC). Statistically significant differences were found both within and among the test groups. Group CD performed statistically significantly different from group LU for marginal fit (MA) and axial fit (AX) ( p < 0.05). For occlusal fit (OC), no statistically significant differences were found within all three test groups ( p > 0.05). Deviation pattern for differences was visually analyzed with a color‐coded scheme for each restoration. Conclusions Statistically significant differences were found for different CAD/CAM materials if the CAM procedure was identical. Within the limitations of this study, the choice of CAD/CAM material may influence the fitting accuracy of CAD/CAM‐fabricated restorations.